Rework logging

Makefile

@@ -8,7 +8,7 @@ CFLAGS  += -Wall -Wextra
 LDLIBS  += -pthread -lcurl
 STRIP    = strip
 VERSION  = v0.1
-OBJS     = alertik.o events.o env_events.o notifiers.o
+OBJS     = alertik.o events.o env_events.o notifiers.o log.o
 
 ifeq ($(LOG_FILE),yes)
 	CFLAGS += -DUSE_FILE_AS_LOG

alertik.c

@@ -5,7 +5,6 @@
 
 #define _POSIX_C_SOURCE 200809L
 #include <errno.h>
-#include <fcntl.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -22,6 +21,7 @@
 #include "alertik.h"
 #include "events.h"
 #include "env_events.h"
+#include "log.h"
 #include "notifiers.h"
 
 /* Uncomment/comment to enable/disable the following settings. */
@@ -29,7 +29,6 @@
 
 #define FIFO_MAX    64
 #define SYSLOG_PORT 5140
-#define LOG_FILE    "log/log.txt"
 
 /* Circular message buffer. */
 static struct circ_buffer {
@@ -40,80 +39,11 @@ static struct circ_buffer {
 
 /* Sync. */
 static pthread_mutex_t fifo_mutex        = PTHREAD_MUTEX_INITIALIZER;
-static pthread_mutex_t log_mutex         = PTHREAD_MUTEX_INITIALIZER;
 static pthread_cond_t fifo_new_log_entry = PTHREAD_COND_INITIALIZER;
 
 /* Misc. */
 #define LAST_SENT_THRESHOLD_SECS 10  /* Minimum time (in secs) between two */
 time_t time_last_sent_notify; /* notifications. */
-static int curr_file;
-
-//////////////////////////////// LOGGING //////////////////////////////////////
-
-/* There should *always* be a corresponding close_log_file() call. */
-static inline void open_log_file(void)
-{
-	struct stat sb;
-
-	pthread_mutex_lock(&log_mutex);
-		if (curr_file == STDOUT_FILENO)
-			return;
-
-		if (stat("log", &sb) < 0)
-			if (mkdir("log", 0755) < 0)
-				return;
-
-		curr_file = openat(AT_FDCWD, LOG_FILE,
-			O_WRONLY|O_CREAT|O_APPEND, 0666);
-
-		if (curr_file < 0)
-			curr_file = STDOUT_FILENO; /* fallback to stdout if can't open. */
-}
-
-/* This should *always* be called *after* a call to open_log_file(). */
-static void close_log_file(void)
-{
-		if (curr_file || curr_file == STDOUT_FILENO)
-			goto out;
-
-		fsync(curr_file);
-		close(curr_file);
-out:
-	pthread_mutex_unlock(&log_mutex);
-}
-
-char *get_formatted_time(time_t time, char *time_str)
-{
-	strftime(
-		time_str,
-		32,
-		"%Y-%m-%d %H:%M:%S",
-		localtime(&time)
-	);
-	return time_str;
-}
-
-void log_msg(const char *fmt, ...)
-{
-	char time_str[32] = {0};
-	va_list ap;
-
-	open_log_file();
-		dprintf(curr_file, "[%s] ", get_formatted_time(time(NULL), time_str));
-		va_start(ap, fmt);
-		vdprintf(curr_file, fmt, ap);
-		va_end(ap);
-	close_log_file();
-}
-
-static inline void print_log_event(struct log_event *ev)
-{
-	char time_str[32] = {0};
-	open_log_file();
-		dprintf(curr_file, "\n[%s] %s\n",
-			get_formatted_time(ev->timestamp, time_str), ev->msg);
-	close_log_file();
-}
 
 /////////////////////////////////// NETWORK ///////////////////////////////////
 static int push_msg_into_fifo(const char *msg, time_t timestamp);
@@ -250,12 +180,7 @@ int main(void)
 	pthread_t handler;
 	int fd;
 
-	atexit(close_log_file);
+	log_init();
-
-#ifndef USE_FILE_AS_LOG
-	curr_file = STDOUT_FILENO;
-#endif
-
 	setup_notifiers();
 	init_environment_events();
 

log.c

@@ -0,0 +1,98 @@
+/*
+ * Alertik: a tiny 'syslog' server & notification tool for Mikrotik routers.
+ * This is free and unencumbered software released into the public domain.
+ */
+
+#include <ctype.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <pthread.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#include "events.h"
+#include "log.h"
+
+static pthread_mutex_t log_mutex = PTHREAD_MUTEX_INITIALIZER;
+static int curr_file;
+
+/* There should *always* be a corresponding close_log_file() call. */
+static inline void open_log_file(void)
+{
+	struct stat sb;
+	pthread_mutex_lock(&log_mutex);
+		if (curr_file == STDOUT_FILENO)
+			return;
+
+		if (stat("log", &sb) < 0)
+			if (mkdir("log", 0755) < 0)
+				return;
+
+		curr_file = openat(AT_FDCWD, LOG_FILE,
+			O_WRONLY|O_CREAT|O_APPEND, 0666);
+
+		if (curr_file < 0)
+			curr_file = STDOUT_FILENO; /* fallback to stdout if can't open. */
+}
+
+/* This should *always* be called *after* a call to open_log_file(). */
+static void close_log_file(void)
+{
+		if (curr_file || curr_file == STDOUT_FILENO)
+			goto out;
+
+		fsync(curr_file);
+		close(curr_file);
+out:
+	pthread_mutex_unlock(&log_mutex);
+}
+
+/**/
+char *get_formatted_time(time_t time, char *time_str)
+{
+	strftime(
+		time_str,
+		32,
+		"%Y-%m-%d %H:%M:%S",
+		localtime(&time)
+	);
+	return time_str;
+}
+
+/**/
+void log_msg(const char *fmt, ...)
+{
+	char time_str[32] = {0};
+	va_list ap;
+
+	open_log_file();
+		dprintf(curr_file, "[%s] ", get_formatted_time(time(NULL), time_str));
+		va_start(ap, fmt);
+		vdprintf(curr_file, fmt, ap);
+		va_end(ap);
+	close_log_file();
+}
+
+/**/
+void print_log_event(struct log_event *ev)
+{
+	char time_str[32] = {0};
+	open_log_file();
+		dprintf(curr_file, "\n[%s] %s\n",
+			get_formatted_time(ev->timestamp, time_str), ev->msg);
+	close_log_file();
+}
+
+/**/
+void log_init(void) {
+	atexit(close_log_file);
+#ifndef USE_FILE_AS_LOG
+	curr_file = STDOUT_FILENO;
+#endif
+}

log.h

@@ -0,0 +1,19 @@
+/*
+ * Alertik: a tiny 'syslog' server & notification tool for Mikrotik routers.
+ * This is free and unencumbered software released into the public domain.
+ */
+
+#ifndef LOG_H
+#define LOG_H
+
+	/* Uncomment/comment to enable/disable the following settings. */
+	// #define USE_FILE_AS_LOG           /* stdout if commented. */
+
+	#define LOG_FILE "log/log.txt"
+
+	extern char *get_formatted_time(time_t time, char *time_str);
+	extern void print_log_event(struct log_event *ev);
+	extern void log_msg(const char *fmt, ...);
+	extern void log_init(void);
+
+#endif /* LOG_H */